Can a young man, who has been destroyed by his sins after abandoning prayer and fasting and committing major sins and publicly boasting about them, repent and return to his Lord, especially after reading a prophetic hadith about the unforgivable nature of those who openly commit sins, and what must he do to repent and become committed?

The door of repentance is open, no matter how great the sin. One must hasten to sincere repentance for neglecting prayers and fasting, commit to performing them, frequently remember death and what comes after it, and seek righteous companionship. You are not obligated to obey your father in forsaking marriage if you fear hardship; rather, marriage is obligatory in this case.